Rotary casting-machine mold



W. A. OUBRIDGE.

ROTARY CASTING MACHINE MOLD.

APPLICATION FILED lULY5| I921.

Patented June 6, 1922.

a STATES PATENT OFFICE.

ROTARY"CASTING-MACHINE MOLD.

Specification of Letters l'atent.

Patented June 6, 1922.

Application filed July 5, 1921. Serial No. 482,498.

To all whom it my concern:

Be it known that I, WILLIAM ARTHUR OU- BRIDGE, a subject of the King ofGreat Britain and Ireland, residin at Coventry, in the county'ofWarwick, ngland, have invented new and useful Improvements in RotaryCasting-Machine Molds, of which the following is a specification.

This invention relates to rotary casting machine molds of the kind inwhich the mold-parts separate in the direction of their axis, andespecially that kind of machine mold in which the metal is pressed whenmolten into shape by centrifugal force due to the rapid rotation of themold. Such a machine forms the subject of the specifications of aBritish Patent, No. 118,304 and of a United States Patent, No.1,325,039, both granted to William Arthur Oubridge. According to thosespecifications the separating mold-parts are held together by pressureapplied axially to hold a front-plate carried by ball-bearings and amold proper, carried by a sleeve, in frictional contact each with theother. In other machines of the rotary type the front-plate has hithertobeen bolted or hinged to the mold by which alone it was carried.

Where the front-plate and mold are held together by frictional contactand axial pressure only, as in the case above specified,

great strain is thrown on the ball-bearings which, moreover, owing totheir proximity to the hot mold, it is feared may rapidly wear, fail orotherwise give trouble. Moreover, such bearings are very expensive,especially when applied to large machines. Otherwise this is asatisfactory construction for molds such as specified and for thewithdrawal therefrom of the castings which, being necessarily thin, mustbe removed from the mold immediately they are set, in order to preventchilling of their surfaces to an extent that would so harden them as toprevent the subsequent use of. cutting tools upon them. The method ofbolting-or hinging the front-plate in place, on the other hand, while itinvolves no strain on any bearlng, yet necessltates opening and closingof the mold by hand, and, owing to the length of time required in thisoperation, the surface of the casting is jeopardized by the rapidcooling which continues while it remains in the mold. Anotherdisadvantage attending the hinging of the mold-part, say a door, that itnecessitates free room in which the door part may swing, thus deprivingthe machine of a valuable, otherwise available space, renders it bulkyand also tends to restrict the employment of means for mechanicallyhandling the casting. I

The object of this invention is to provide a. mechanical means forattaching and detaching the parts of molds such as above specified; forexample a bayonet joint as has been proposed for the two-partcentrifugal mold cases used in making phonograph records, or theinterrupted screw threads of a gun breech and block, for allowing quickwithdrawal of the castings therefrom as soon as they are set; to embodythe advantages possessed by mold-parts held against each other by axialpressure and friction only and also those of mold-parts hitherto boltedor hinged together, while avoiding the disadvantages of both these meansof attachment and detachment.

According to this invention a centrifugal metal casting machine moldshas its separable parts attached together for the casting operation bymeans of a device adapted to draw the said parts one toward the other orto force them apart, when they are relatively moved about their commonaxis, and a mechanically operated gripping means is employed for holdingone of said parts stationary while the other part is being movedrelatively thereto.

A carriage on the casting machine bed is furnished with a means forholding one mold-part, for example the front-plate, fast when desired,and for supporting it while the casting is'being removed from the mold.

In one example of a casting machine mold constructed according to thisinvention and shown in the accompanying drawings Fig. 1 is a side viewpartly in vertical axial section thereof, and

Fig. 2 is an end view of the machine shown in Fig. 1.

The parts of the mold are formed by a hollow cylindrical member 1 amold-piston Thus, a cross section of the casting space is shown betweenthe radial Walls 5 and 6,

the cylindrical-wall 4 and the dotted line 7.

The parts 1 and 3 of the mold are attached one to the other by a bayonetjoint device, the pins 8, 8 of which are mounted on the part 1 and carryanti-friction rollers adapted to engage slots 9 cut in a flange 10' thatforms part of the front-plate 3. The said plate 3 is formed with agroove 11 at its periphery within which the circular gripping jaws 12,12 of levers 13, 13 are adapted to fit. These levers 13, 13 are pivotedat their lower ends 14, 14 to a slide 15 adapted for movement along themachine bed 16 by rack and pinion 17 and 18 respectively. Between thesaid jaws 12, 12 and the pivots at 14, 14 the former. are furnished withnuts 19, 19 for engaging right and left hand screws on aspindle 20furnished with a hand-wheel 21, so that by rotating this wheel the jaws12, 12 may be caused to grip the front-plate 3 and hold it immovable.

The mold 1 is carried by a sleeve 22 furnished with heat dissipatinggills 23, and having journals adapted to rotate in bear ings 24, 24 on acarriage 25. The mold-piston 2 is mounted on a rod 26 which passesthrough the sleeve 22 and is furnished with a compressed air piston 27adapted to Work in a cylinder 28 fixed at the end of the machinefarthest from the mold-piston 2.

On the sleeve between the bearing 24, 24 is mounted a strap and brakepulley 29 adapted to be driven by a shifting band 30 and also to bebraked by a: strap brake 31.

The cylinder 28 is furnished with an admission and exhaust pipe 32 andalso with a three way valve (not shown). It is moreover, furnished witha compression spring 33 adapted to return the piston 27 when thecompressed air is allowed to escape.

To operate the machine shown in the drawings for (raging a piston ring,the moldparts 1 and 3 are first caused to engage by turning onerelatively to the other when they ,are in cont-act and pressed together.Next the screw spindle 20 is turned so as topartly open the jaws 12, 12of the lever 13 and release the front-plate or mold-part 3. The rotationof the part 1 is then started for example by shifting the band 30 to thefast pulley of the second shaft (not shown). The pin 8 and its rollerthen enter further into the slot 9, and owing to the inertia of the part3 or to the braking effect of the jaws 12. 12 they press on the righthand of the said slot 9 and so draw the parts 1 and together; the moretightly as the inertia is greater or the braking efi'ect increases.

that the jaws 12, 12

., The m'o-ld is then rotated rapidly andthe meta-l poured into thecasting space therein by means of a common pourer spout, theend of whichpasses through the mold'part or cover 3,;as usual. The rotationis-continued until the casting is set, then the driving band 30 isshifted to the loose pulley of the second shaft and the band-brake 31applied and,

.when the'mold-parts 1, 2 and 3 have been grip the front plate or cover3 and the mold-part -1' is turned backward to disengage the'parts 1 and3 so that the pin 8 and the roller leave the slot 9. The pinion 18 isthen turnedby means of the capstan head fast on the pinion shaft, tomove the carriage 15, and mold-part 3, now carried thereby, clear of thepart 1 so that the casting when ejected may fall outbetween themold-parts l and 3.

To eject the casting compression air is admitted to the cylinder 28 toforce the air piston 27, and consequently the mold-piston 2 to theleft-hand so that the casting is slidden axially from the mold-part 1.The air is then released from the, cylinder 28-and the spring 33withdraws the pistons27 and 2 and their common rod 26 until these partsare again in the positions required for the casting operation which maythen recommence. 9 5

1. In a centrifugal metal-casting machine the combination of amold-having separable mold-parts attached together for the castingarrested, the screw spindle 20 is turned so operation by means of adevice adapted to draw the said mold-parts one toward the other or toforce them apart when they are relatively moved about their common axisand a. mechanically operated grippingmeans" for holding one of saidmold-parts stationary whilst the other mold-part is being movedrelatively thereto, substantially as described. I

2; In a centrifugal metal casting machine the. combination of amoldhaving separable mold-parts attached together for the casting operationby means of a. device adapted to draw the said mold-parts one toward theother or to force them apartwhen theyare relatively moved about theircommon axis and a mechanically operated gripping de-- vice for holdingone mold-part and com rising a pair of levers having-opposed jawsadapted-to grip the said mold-part between them at a part thereof thatis concentric tothe mold axis and means for forcing the jaws, one towardor one away from the other, substantially as described.

3. In a centrifugal metal casting machine the combination of'a moldhaving separable mold-parts attached together for the casting operationby abayonet joint device the pins on one part ofwhich engage slots onthe other part to draw the said mold parts one toward the other or toforce them apart when they are relatively moved about their common axis,with a mechanically operated gripping device for holding and releasingone mold-part and comprising a pair of levers having opposed jawsadapted to grip the said mold-part between them, pivoted at their endsopposite said jaws and moved apart, or one toward the other by turninga. shaft having right and left hand screws each. engaging acorresponding nut pivoted to one 10 of the said levers between the endsthereof, substantially as described and for the purposes specified.

WILLIAM A. OUBRIDGE.

